1. Technical Field
The present invention relates to a liquid discharge apparatus, such as an ink jet recording apparatus, and the like and a method of controlling a liquid discharge apparatus. In particular, the invention relates to a liquid discharge apparatus provided with a filter that filters liquid to be discharged from a nozzle of a liquid discharge head, and a method of controlling a liquid discharge apparatus.
2. Related Art
A liquid discharge apparatus is an apparatus that includes a liquid discharge head and that discharges (ejects) various kinds of liquid from the liquid discharge head. As the liquid discharge apparatus, there are image recording apparatuses, for example an ink jet printer, an ink jet plotter, and the like. However, the liquid discharge apparatus has recently been applied to various manufacturing apparatuses by taking advantage of the feature of enabling a tiny droplet to precisely impact on a predetermined position. For example, the liquid discharge apparatus is applied to a display manufacturing apparatus for manufacturing a color filter of a liquid crystal display, and the like, to an electrode forming apparatus for forming an electrode of an organic electro luminescence (EL) display, a field emission display (FED), and the like, and to a chip manufacturing apparatus for manufacturing a biochip (biochemical element). The recording head for the image recording apparatus discharges liquid ink, and the color material discharge head for the display manufacturing apparatus discharges each color material solution of R (Red), G (Green), and B (Blue). Also, the electrode material discharge head for the electrode forming apparatus discharges a liquid electrode material, and the bio-organic material discharge head for the chip manufacturing apparatus discharges a bio-organic material solution.
Here, in the above-described liquid discharge apparatus, a filter for filtering liquid is generally provided in the flow path from a liquid storage member storing liquid to a nozzle of the liquid discharge head. The filter removes foreign substances, such as bubbles, and the like in the liquid. Thereby, the occurrence of hindrance to liquid discharge, which is caused by foreign substances, and the like that clog the flow path of the liquid discharge head, is suppressed. However, if the filter is clogged by the accumulation of foreign substances, and the like, the liquid is not smoothly supplied to the nozzle, and thus liquid discharge at the nozzle might be adversely affected. Accordingly, various proposals have been made regarding a configuration for detecting clogging of the filter (for example, refer to JP-A-5-116337, JP-A-2011-167873, and JP-A-2006-076136). In the configuration disclosed in JP-A-05-116337, clogging of the filter is detected on the basis of the pressure difference between the respective pressure sensors of the upstream side and the downstream side on the supply route of the liquid. Also, in the configuration disclosed in JP-A-2011-167873, clogging of the filter is detected on the basis of the drive state of the pump in the circulation system path of the liquid. JP-A-2006-076136 discloses the configuration in which a flow path in which a filter is disposed is provided with a bypass flow path that bypasses the filter, and clogging of the filter is detected on the basis of detection of a liquid flow in the bypass flow path caused by the clogging of the filter.
However, in these configurations of the related art, it has been necessary to additionally provide a special part or to employ a specific structure in order to detect clogging of the filter.